有参构造惹的祸 -无参构造

知识点   ：    对象有参数构造后，就不会自动加载无参构造

刚开始项目运行的好好的，突然就一直报下面错误

出现的结果  ：

org.springframework.dao.DataIntegrityViolationException: Error attempting to get column 'question_id' from result set. Cause: java.sql.SQLDataException: Unsupported conversion from LONG to java.sql.Timestamp

; Unsupported conversion from LONG to java.sql.Timestamp; nested exception is java.sql.SQLDataException: Unsupported conversion from LONG to java.sql.Timestamp

at org.springframework.jdbc.support.SQLExceptionSubclassTranslator.doTranslate(SQLExceptionSubclassTranslator.java:84)

at org.springframework.jdbc.support.AbstractFallbackSQLExceptionTranslator.translate(AbstractFallbackSQLExceptionTranslator.java:72)

at org.springframework.jdbc.support.AbstractFallbackSQLExceptionTranslator.translate(AbstractFallbackSQLExceptionTranslator.java:81)

at org.mybatis.spring.MyBatisExceptionTranslator.translateExceptionIfPossible(MyBatisExceptionTranslator.java:88)

at org.mybatis.spring.SqlSessionTemplate$SqlSessionInterceptor.invoke(SqlSessionTemplate.java:440)

at com.sun.proxy.$Proxy140.selectList(Unknown Source)

at org.mybatis.spring.SqlSessionTemplate.selectList(SqlSessionTemplate.java:223)

at com.baomidou.mybatisplus.core.override.MybatisMapperMethod.executeForMany(MybatisMapperMethod.java:177)

at com.baomidou.mybatisplus.core.override.MybatisMapperMethod.execute(MybatisMapperMethod.java:78)

at com.baomidou.mybatisplus.core.override.MybatisMapperProxy.invoke(MybatisMapperProxy.java:96)

at com.sun.proxy.$Proxy153.selectList(Unknown Source)

at cn.tedu.straw.portal.test.mapper.TestTeacherQuestionMapper.selectOne(TestTeacherQuestionMapper.java:32)

at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)

at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)

at java.lang.reflect.Method.invoke(Method.java:498)

at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)

at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)

at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)

at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)

at org.springframework.test.context.junit4.statements.RunBeforeTestExecutionCallbacks.evaluate(RunBeforeTestExecutionCallbacks.java:74)

at org.springframework.test.context.junit4.statements.RunAfterTestExecutionCallbacks.evaluate(RunAfterTestExecutionCallbacks.java:84)

at org.springframework.test.context.junit4.statements.RunBeforeTestMethodCallbacks.evaluate(RunBeforeTestMethodCallbacks.java:75)

at org.springframework.test.context.junit4.statements.RunAfterTestMethodCallbacks.evaluate(RunAfterTestMethodCallbacks.java:86)

at org.springframework.test.context.junit4.statements.SpringRepeat.evaluate(SpringRepeat.java:84)

at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)

at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:251)

at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:97)

at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)

at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)

at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)

at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)

at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)

at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61)

at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:70)

at org.junit.runners.ParentRunner.run(ParentRunner.java:363)

at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:190)

at org.junit.runner.JUnitCore.run(JUnitCore.java:137)

at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)

at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)

at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)

at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)

Caused by: java.sql.SQLDataException: Unsupported conversion from LONG to java.sql.Timestamp

at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:114)

at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:97)

at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:89)

at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:63)

at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:73)

at com.mysql.cj.jdbc.exceptions.SQLExceptionsMapping.translateException(SQLExceptionsMapping.java:96)

at com.mysql.cj.jdbc.result.ResultSetImpl.getTimestamp(ResultSetImpl.java:903)

at com.mysql.cj.jdbc.result.ResultSetImpl.getTimestamp(ResultSetImpl.java:948)

at com.zaxxer.hikari.pool.HikariProxyResultSet.getTimestamp(HikariProxyResultSet.java)

at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)

at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)

at java.lang.reflect.Method.invoke(Method.java:498)

at org.apache.ibatis.logging.jdbc.ResultSetLogger.invoke(ResultSetLogger.java:69)

at com.sun.proxy.$Proxy248.getTimestamp(Unknown Source)

at org.apache.ibatis.type.DateTypeHandler.getNullableResult(DateTypeHandler.java:39)

at org.apache.ibatis.type.DateTypeHandler.getNullableResult(DateTypeHandler.java:28)

at org.apache.ibatis.type.BaseTypeHandler.getResult(BaseTypeHandler.java:81)

at org.apache.ibatis.executor.resultset.DefaultResultSetHandler.createUsingConstructor(DefaultResultSetHandler.java:671)

at org.apache.ibatis.executor.resultset.DefaultResultSetHandler.createByConstructorSignature(DefaultResultSetHandler.java:654)

at org.apache.ibatis.executor.resultset.DefaultResultSetHandler.createResultObject(DefaultResultSetHandler.java:618)

at org.apache.ibatis.executor.resultset.DefaultResultSetHandler.createResultObject(DefaultResultSetHandler.java:591)

at org.apache.ibatis.executor.resultset.DefaultResultSetHandler.getRowValue(DefaultResultSetHandler.java:397)

at org.apache.ibatis.executor.resultset.DefaultResultSetHandler.handleRowValuesForSimpleResultMap(DefaultResultSetHandler.java:354)

at org.apache.ibatis.executor.resultset.DefaultResultSetHandler.handleRowValues(DefaultResultSetHandler.java:328)

at org.apache.ibatis.executor.resultset.DefaultResultSetHandler.handleResultSet(DefaultResultSetHandler.java:301)

at org.apache.ibatis.executor.resultset.DefaultResultSetHandler.handleResultSets(DefaultResultSetHandler.java:194)

at org.apache.ibatis.executor.statement.PreparedStatementHandler.query(PreparedStatementHandler.java:65)

at org.apache.ibatis.executor.statement.RoutingStatementHandler.query(RoutingStatementHandler.java:79)

at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)

at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)

at java.lang.reflect.Method.invoke(Method.java:498)

at org.apache.ibatis.plugin.Plugin.invoke(Plugin.java:63)

at com.sun.proxy.$Proxy236.query(Unknown Source)

at com.baomidou.mybatisplus.core.executor.MybatisSimpleExecutor.doQuery(MybatisSimpleExecutor.java:67)

at org.apache.ibatis.executor.BaseExecutor.queryFromDatabase(BaseExecutor.java:324)

at org.apache.ibatis.executor.BaseExecutor.query(BaseExecutor.java:156)

at com.baomidou.mybatisplus.core.executor.MybatisCachingExecutor.query(MybatisCachingExecutor.java:155)

at com.github.pagehelper.PageInterceptor.intercept(PageInterceptor.java:143)

at org.apache.ibatis.plugin.Plugin.invoke(Plugin.java:61)

at com.sun.proxy.$Proxy235.query(Unknown Source)

at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:147)

at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:140)

at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)

at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)

at java.lang.reflect.Method.invoke(Method.java:498)

at org.mybatis.spring.SqlSessionTemplate$SqlSessionInterceptor.invoke(SqlSessionTemplate.java:426)

... 37 more

@Data

@TableName("teacher_question")

public class  TeacherQuestion implements Serializable {

    private static final long serialVersionUID = 1L;

    @TableId(value = "id", type = IdType.AUTO)

    private Integer id;

    @TableField("teacher_id")

    private Integer teacherId;

    @TableField("question_id")

    private Integer questionId;

    @TableField("createtime")

    private Date createtime;

    public TeacherQuestion(Integer teacherId, Integer questionId, Date createtime) {

        this.teacherId = teacherId;

        this.questionId = questionId;

        this.createtime = createtime;

    }

}

上面是业务需要自己构造了一个有参的函数，就会报上面的错误

解决方案：        测试ok

解决的办法是：给该实体类手动添加一个无参构造方法。

public     TeacherQuestion(){

    }